The present invention relates to an operation microscope having an objective of variable focal length and a housing which is mounted to a support. The housing contains means on the observation-ray path for splitting and deflecting the beam, to serve at least two observation tubes.
Operation microscopes have acquired widespread use in all fields of microsurgery. This circumstance can be attributed to an increase in social awareness of the needs for human care and attention, and to advances in medicine, particularly the refinement of methods of operation. Refinement and complexity of methods of operation confront the surgeon with demands which, in many cases today, he can satisfy only by employing a second surgeon and using apparatus having greater technical possibilities and an increased number of functions. And at the same time, the extent and expense of education required for the training of surgeons have soared.
In recognition of these factors, particularly during the last two decades, operation microscopes have been very substantially expanded and encumbered by attachments and/or by modifications adapted to the requirements of individual disciplines.
The simplest embodiment of an operation microscope consists of an objective of long back focus and a binocular observation tube, combined in a housing. This housing is fastened to a floor- or a wall- or a ceiling mounted support. Such a microscope can be directed rapidly and simply to the object field to be observed, since no large masses need be moved, and suspension can be effected at least approximately at the center of gravity.
To meet a growing number of requirements, these simple universal operation microscopes have been substantially expanded in their function during the last few years, and as a result, size and weight of the apparatus have also increased greatly.
To illustrate such expansion of operation microscopes, mention may be made of magnification changers, illuminating devices and, in particular, co-observation, television and photographic devices. Such additional attachments are frequently greater in volume and weight than the operation microscope itself.
It is clear that all attachments make a thus-equipped operation microscope more difficult to use. Since the surgeon must have both his hands free, the required three-dimensional viewing adjustment of the operation microscope on the object is effected purely mechanically, via suitable movement of the suspension, i.e., of the support. In this case, large weights must be moved, resulting in considerable shifts in the center of gravity which must be reliably accommodated by the suspension. The supports are therefore made very stable, and are necessarily also very expensive.
Another disadvantage of the known operation microscopes is that, for each adjustment of focus and/or of the direction of observation effected by movement of the entire microscope, the surgeon and his co-observer are forced to move their heads and possibly even to move their entire upper bodies.
West German Patent application (Offenlegungsschrift) No. 2,439,820, discloses an operation microscope in which focusing no longer requires movement of the microscope itself. This microscope has an objective of variable back focus, comprising a fixed negative member and a positive member, which is axially displaceable for focusing purposes. However, this microscope does not avoid the disadvantage that the entire microscope must be swung in order to adjust the direction of observation, so that movements of the operator are still necessary.
West German Patent application (Offenlegungsschrift) No. 2,440,958 discloses an operation microscope which is so swingably mounted on its suspension that the swing axis of the microscope lies in the exit axis of partial beams directed to co-observer devices and/or to a photographic, motion-picture or television camera. Such attachments can thus be firmly connected with the microscope suspension or the support or be swingably connected to the microscope. They thus do not constitute an obstacle for the surgeon when the operation microscope is swung. The surgeon, however, is still forced to move his head and his upper body when the microscope is swung or displaced for fucusing.